Bicycle Mechanics - New SRAM 10sp Cassettes on 9sp Ultegra?

Hi,

I was wondering if anyone knows a definitive answer to whether the 10sp SRAM cassettes such as those included in the Rival/Force groupsets would fit onto a FH-6500 Ultegra Rear Hub?

Assuming the new SRAM cassettes are 'exactly' compatible with Shimano 10sp cassettes, Shimano states that _all_ new 10sp shimano cassettes will fit on FH-6600/ 8-9sp Freehubs. However, Shimano also says that the WH-6500 wheelset (which seems to use the FH-6500 freehub body) is not compatible with some of the 10sp Shimano Cassettes (11-23 and 12-23 gear combos). I'm aiming to get a 11-23 SRAM Rival Cassette, so I'm afraid it won't fit onto my FH-6500 hub...

Shimano Compatiblity Chart:
http://bike.shimano.com/publish/content/cycle/sac/us/en/technical_service/compatibility_charts/road_compatibility.-MainContent-0003-DownloadFile.tmp/9_10sp%20cs_fh_wh%20compatibility.pdf.pdf

Shimano WH-6500 Parts List:
http://www.starbike.com/images/Shimano/PDF-Dateien/WH_6500_R.pdf

Shimano FH-6500 Parts List:
http://techdocs.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/FH/EV-FH-6500-1679_v1_m56577569830611839.pdf

Shimano FH-6600 Parts List:
http://techdocs.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/FH/EV-FH-6600-2348_v1_m56577569830608914.pdf

Thanks for any help you guys can be.

SRAM cassettes will fit shallow splined Shimano freehub bodies.

The FH-6500 limit seems to be the 23T cog as none of the XXx23 10-speed cassettes are listed as compatible with it. I don't know why but if Shimano says their 23T largest cog cassettes won't work, it's probably safe to assume SRAM's won't either. You may want to contact Shimano directly and ask what the problem is.

Thanks for the replies guys. It does seem like SRAM cassettes will fit shallow splined shimano hubs as per a review I read where the reviewer couldn't fit the SRAM cassettes on a Mavic 10spd hub due to spine issues. That should mean that they'll fit on the FH-6500 as 9spd hubs run shallow spines. But HillRider is also right, there definitely seems to be an incompatibility with the lower tooth top gears (23) with the FH-6500?

I'm having trouble finding the contact information for Shimano or even SRAM for that matter. Anyone know what they are or where I can find it?

Thanks for all the info so far!

Here is Shimano's US headquarters.

Shimano American Corp.
1 Holland Dr.
Irvine, CA 92618
949-951-5003